Process of electrically treating gases.



PAT

ENTED OCT. 18 1904. K. BIRKELAND. PROCESS OF ELEGTRIGALLY TREATINGGASES.

APPLICATION FILED APR. 2, 1904.

N0 MODEL.

UNITED STATES Patented October 18, 1904.

PATENT OFFICE.

PROCESS OF" ELECTRICALLY TREATING GASES.

SPECIFICATION forming part of Letters Patent No. 772,862, dated October18, 1904.

Original application filed June 15, 1903, Serial No. 16I,616. Dividedand this application filed April 2, 1904. Serial No. 201,267.

(No specimens.)

To tlZ whom it may concern.-

Be it known that I, KRISTIAN BIRKELAND, a subject of the King of Swedenand Norway, residing at Christiania, Norway, have invented certain newand useful Improvements in Processes of Electrically Treating Gases; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use thesame,

2o sary for such processes-for instance, the nitrification of air bymeans of electric arcs established within the gas; but this methodhasproven a commercial failure, for the reason that the energy consumedby an ordinary 2 5 'electric arc istoo great relatively to the units ofheat utilized in the chemical process by the gases treated. .Ithas not,therefore, been possible up to this date to utilize electric energy in asingle powerful are for the production, for instance, of nitriccompounds from the atmosphere in an economical manner. Experiments arealso known by which comparatively great quantities of electrical energyhave been distributed among a very large number of thin electric arcs,each representing only a very small amount of energy and currentstrength in order to obtain a high efiiciency and better economicalresults.

My invention has for its object a process 4 whereby theefliciency of anelectric are at a single set of electrodes for causing chemicalreactions at temperatures of about 1,500 to 3,000 centigrade isenormously increased.

My invention is based upon the fact that electrical discharges producedbetween electrodes placed within a magnetic field may be dispersed bythe action of the magnets. By

my experiments I have found that an electric arc of high or low tensionmay be dilatedor spread into a large permanent flame having the shape ofa sheet or a disk of a volume several hundred times as large as aregular or primary arc of the same energy when the electrodes are placedin a suitable manner in a powerful magnetic fieldfor instance, betweenthe poles of a magnet and transverse to the flux of said field. In thisway I am able to transform a great part of the electrical energy intoheat capable of being absorbed by certain gases, as chemical energyunder conditions which are attended by valuable chemical reactions. Thisis due to the fact that the efliciency of a flame in endothermicalchemical processes is a function of the ratio between the volume and thetemperature of the flame. By my process I am able to have furnaces atcontinuous work with several hundred kilowatts at each flame, the heatbeing economically utilized, a result which was not heretofore possibleunless vthe energy employed for each arc was only very small.

In carrying out my process I may make use of a great variety ofapparatus, and in my application, Serial No. v161,616, filed June 15,1903, of which this is a divisional application, I have describedseveral forms of such apparatus.

For the purpose of explaining my process more clearly I shall, however,de- Q scribe one form of apparatus, which is shown in the annexeddrawings. In the drawings, Figure 1 is a perspective diagrammatic view,.partly in section, illustrating the main features of an'apparatus forcarrying out my invention; Fig. 2, a vertical section through anapparatus having a number of consecutive chambers arranged between thepoles of a magnet; Fig. 3, a vertical sec-- tion at right angles to Fig.2 through the said chambers, and Fig. 4 a horizontal section through thesame.

In Fig. 1, M represents an electromagnet,

(one pole of which is broken away,) and C C electrodes which are placedin the field between the two poles of the magnet M. These electrodes areinserted in an electrical circuit, as indicated, and are inclosed withina hous between the poles of the magnet. This housing has an air or gasinlet at T and an outlet at'U. With a suitable distance between thepoints of the electrodes and a suitable current as well on theelectrodes as on the magnets there will be formed a dispersed are, asindicated by the curves A, the are being in the shape of a permanentsheet. or, disk at right angles to the lines of force of the magneticfield. 'If currents of high voltage-for instance, five thousandvolts-are used, I have found it suitable to place the electrodes at afixed distance of some millimeters apart. As explained in my aforesaidapplication of same date I may also make use of electrodes having rapidperiodic movements.- In this case I may also make use of low-tensioncurrent. The air or gas coming in at T will pass through the flame inthe direction of its plane and will thereby be exposed to a veryenergetic action of long duration. Figs. 2, 3, and 4 show amultiple-chamber arrangement for this purpose. M represents an annularelectromagnet. Instead of an electromagnet a compound permanent magnetmay be used. Between the poles of the electromagnet is placed a tubularhousing 0, which is divided into a series of vertical channels P bypartitions R, which alternately extend to the top and the bottomplatesand alternately leave a space open between their ends and said plates,so" that a zigzag channel is formed through which air is passed. (SeeFigs. 2 and 3.) The housing and the partitions within the same shouldwholly or partly be made of insulating and fireproof material. Withineach of said channels P are placed electrodes C C, which may be providedwith horns B B, formed out of strips of platinum, fixed so as to form anangle with the electrode at opposite sides, whereby the size of the arcmay be increased. When a current of very high voltage is used, thecurrent may be sent partly or wholly in series through the whole set ofelectrodes. The air may be passed either directly in parallel throughall the flat channels or wholly or partly in series through the same, asshown in Fig. 1 of the drawings, the air passing in this case upwardpast the first arc, downward past the second, upward past the third, andso on. In this way the same quantity of air will make contact with agreat number of arcs. If it is desired to bring the gases in contactwith a still greater number of arcs, a plurality of such arc systemshaving each their separate electromagnet may be disposed with suitableintervals in vertical or horizontal rows.

Having thus fully described my invention,

tact with said are.

wh t I claim as new, and desire to secure by Letters Patentof the UnitedStates, is-

1 The process which consists'in establishing an electric are, creating amagnetic field adapted to disperse orspread said are and passing acurrent of gas or gases past and in con- 2. The process which consistsin establish ing an electric arc in a magnetic field and transverse tothe flux of the same and passing a cur; rent of gas to be treated pastsaid are and in contact with the same. v

3. The process which consists in establishing an electric arcinasubstantially uniform magnetic field and transverse to the flux ofthe same, and passingacurrent of gas to be treated past said are and incontact with the same.

4. The process of causing chemical reaction in a compound or mixture ofgases, which consists in subjecting such a compound or-mixture to theaction of an electric arc in a magnetic field.

5. The processof causing chemical reaction in a compound or mixture ofgases, which consists in subjecting such a compound or mixture to theaction of an electric arc in a sub stantially uniform magnetic field.

6. The process of causing chemical reaction in a compound or mixture ofgases, which consists in-establishing an arc in a magnetic field andtransverse to the flux of the same, and

.passing a current of the compound or mixture past said are and incontact with the same.

7. The process' which consists in establishing an electric arc,spreading said are by a magnetic field into the form of a sheet, andpassing a current of the gas to be'treated in a direction parallel tothe surface of said sheet and in contact therewith.

8. The process of producing compounds of nitrogen from gases containingnitrogen, which consists in establishing an electric arc in a magneticfield, subjecting said gases to the action of said arc, and thenremoving the resultant compounds of nitrogen.

-9. The process of producing nitrogenoxids from atmospheric air, whichconsists in subjecting said air to the simultaneous action of anelectric arc and a magnetic field and then removing the nitrogen oxidsfrom the remaining products.

In testimony whereof I afiix my signature to this specification in thepresence oftwo witnesses.

Karsrmu BIRKELAND.

Witnesses:

AUG. OLSEN, HENRY 'Bozanawren.-

